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// rights reserved.
//
// This file is part of YAS(https://github.com/niXman/yas) project.
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
//
//
// Boost Software License - Version 1.0 - August 17th, 2003
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
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#ifndef __yas__types__std__variant_serializers_hpp
#define __yas__types__std__variant_serializers_hpp

#if __cplusplus >= 201703L

#include <yas/detail/type_traits/type_traits.hpp>
#include <yas/detail/type_traits/serializer.hpp>
#include <yas/detail/preprocessor/preprocessor.hpp>

#include <variant>

namespace yas {
namespace detail {

/***************************************************************************/

#define __YAS_GENERATE_STD_VARIANT_SWITCH_CB(unused, i, n) \
    case i: { \
        using elem_t = typename std::variant_alternative< \
             i \
            ,std::variant<YAS_PP_ENUM_PARAMS(n, T)> \
        >::type; \
        \
        __YAS_CONSTEXPR_IF ( yas::is_writable_archive<Archive>::value ) { \
            elem_t &elem = std::get<elem_t>(v); \
            __YAS_CONSTEXPR_IF ( F & yas::json ) { \
                ar & YAS_OBJECT(nullptr, elem); \
            } else { \
                ar & elem; \
            } \
        } else { \
            elem_t elem = elem_t(); \
            __YAS_CONSTEXPR_IF ( F & yas::json ) { \
                ar & YAS_OBJECT(nullptr, elem); \
            } else { \
                ar & elem; \
            } \
            \
            v = std::move(elem); \
        } \
        \
        return; \
    };

#define __YAS_GENERATE_STD_VARIANT_SWITCH_FOR_ZERO(n)

#define __YAS_GENERATE_STD_VARIANT_SWITCH_FOR_NONZERO(n) \
    template<std::size_t F, typename Archive, YAS_PP_ENUM_PARAMS(n, typename T)> \
    void std_variant_switch(Archive &ar, std::size_t idx, std::variant<YAS_PP_ENUM_PARAMS(n, T)> &v) { \
        switch ( idx ) { \
            YAS_PP_REPEAT( \
                 n \
                ,__YAS_GENERATE_STD_VARIANT_SWITCH_CB \
                ,n \
            ) \
            default: return; \
        } \
    }


#define __YAS_GENERATE_STD_VARIANT_SWITCH(unused, n, unused2) \
    YAS_PP_IF( \
         YAS_PP_EQUAL(n, 0) \
        ,__YAS_GENERATE_STD_VARIANT_SWITCH_FOR_ZERO \
        ,__YAS_GENERATE_STD_VARIANT_SWITCH_FOR_NONZERO \
    )(n)

YAS_PP_REPEAT( \
     YAS_VARIANT_MAX_VARIANTS \
    ,__YAS_GENERATE_STD_VARIANT_SWITCH \
    ,~ \
)

#undef __YAS_GENERATE_STD_VARIANT_SWITCH_CB
#undef __YAS_GENERATE_STD_VARIANT_SWITCH_FOR_ZERO
#undef __YAS_GENERATE_STD_VARIANT_SWITCH_FOR_NONZERO
#undef __YAS_GENERATE_STD_VARIANT_SWITCH


/***************************************************************************/

template<std::size_t F, typename... Types>
struct serializer<
     type_prop::not_a_fundamental
    ,ser_case::use_internal_serializer
    ,F
    ,std::variant<Types...>
> {
    template<typename Archive>
    static Archive& save(Archive& ar, const std::variant<Types...> &v) {
        const std::size_t idx = v.index();
        __YAS_CONSTEXPR_IF ( F & yas::json ) {
            ar.write("[", 1);
            ar & YAS_OBJECT(nullptr, idx);
            ar.write(",", 1);
            std_variant_switch<F>(ar, idx, __YAS_CCAST(std::variant<Types...> &, v));
            ar.write("]", 1);
        } else {
            ar.write(__YAS_SCAST(std::uint8_t, idx));
            std_variant_switch<F>(ar, idx, __YAS_CCAST(std::variant<Types...> &, v));
        }

        return ar;
    }

    template<typename Archive>
    static Archive& load(Archive& ar, std::variant<Types...> &v) {
        __YAS_CONSTEXPR_IF ( F & yas::json ) {
            __YAS_CONSTEXPR_IF ( !(F & yas::compacted) ) {
                json_skipws(ar);
            }
            __YAS_THROW_IF_BAD_JSON_CHARS(ar, "[");
            std::size_t idx = 0;
            ar & YAS_OBJECT(nullptr, idx);
            __YAS_CONSTEXPR_IF ( !(F & yas::compacted) ) {
                json_skipws(ar);
            }
            __YAS_THROW_IF_BAD_JSON_CHARS(ar, ",");
            std_variant_switch<F>(ar, idx, v);
            __YAS_CONSTEXPR_IF ( !(F & yas::compacted) ) {
                json_skipws(ar);
            }
            __YAS_THROW_IF_BAD_JSON_CHARS(ar, "]");
        } else {
            std::uint8_t idx = 0;
            ar & idx;
            std_variant_switch<F>(ar, idx, v);
        }

        return ar;
    }
};

/***************************************************************************/

} // namespace detail
} // namespace yas

#endif // __cplusplus >= 201703L

#endif // __yas__types__std__variant_serializers_hpp
